Systolic Murmur Overview

Introduction

Systolic murmurs occur during systole (between the first heart sound (S1) and the second heart sound (S2). Systolic murmurs are further classified by timing within systole: mid or late. Holosystolic murmurs are systolic murmurs lasting for all or nearly all of systole.

Mid-Systolic Murmur

Mid-systolic ejection murmurs are often heard with a rising then falling intensity. This is called a crescendo-decrescendo murmur. The murmur sound is due to blood flowing through the semilunar valves.

Late Systolic Murmur

Late systolic murmurs can be best auscultated over the heart's apex. Clicks will often proceed a late systolic murmur because of mitral valve prolapse. Significant (severe) mitral valve prolapse can cause mitral regurgitation.

Holosystolic Murmur

Holosystolic murmurs begin at the first heart sound (S1) and continue to the second heart sound (S2). They are usually high-pitched and are caused by ventricular septal defect, mitral regurgitation or tricuspid regurgitation.

Systolic Murmur Lessons

We offer a complete course on systolic murmurs as well as numerous additional lessons specific systolic murmurs. The table of contents provides quick access to each of the lessons within our systolic murmurs course.